It identifies far-right populist movements such as the Pegida movement which drew tens of thousands to rallies in Germany as exposing European countries to greater risk of terror attacks.

One aspect of the enhanced threat from Islamist terrorism, the authors write "has been increased risk ratings in Germany due to large-scale recurrences of far-right anti-Islam demonstrations. Other European countries have also seen a rise of far-right activist movements and fringe parties that agitate in favour of xenophobic policies."

In January, a planned march by Pegida in Dresden was cancelled after police received evidence of a threat.

The report identifies the rise of IS as playing a key role in the increased terror threat in a number of countries: "The threat posed by returnees from those countries and other theatres of jihad, as well as those radicalised but who remain at home has largely defined the threat."

Scott Bolton, Director, Business Development and Network Relations at Aon Risk Solutions said, "The Aon Terrorism and Political Violence map is a key analytical source which helps our clients understand terrorism risk exposures across the globe."

The ratings are based on data on planned and actual terror attacks compiled over the last 12 months, and analysis from experts at Aon and Risk Advisory Group.